After every flight, UPS pilots fill out a form, called a ‘gripe sheet,’ which tells mechanics about problems with the aircraft.
The mechanics correct the problems, document their repairs on the form, and then pilots review the gripe sheets before the next flight.

Never let it be said that ground crews lack a sense of humor. Here are actual maintenance complaints submitted by UPS pilots (marked with a P) and the solutions recorded (marked with an S) by Maintenance Personnel.

By the way, UPS is the only Major Airline that has never, ever, had an accident.